Permafrost generally forms in regions where the mean annual temperature is below zero degrees Celsius. And the presently large expanse of permafrost has formed over the past 2-3 million years in which long, cold ice ages and short, and somewhat warmer interglacial periods have dominated.

(Recent research indicates that up to 120 billion tons of carbon could release from thawing permafrost this Century due to the warming that is now being caused by human fossil fuel burning. Such a release would roughly equate to 12 years of present fossil fuel burning adding approximately 40 ppm of CO2 equivalent gasses to the Earth’s Atmosphere [adding about 0.4 C to medium term warming and 0.8 C to long term warming]. The risk posed by this additional carbon feedback coming from the Earth System highlights the need to halt fossil fuel burning as swiftly as possible. Image source: The Impact of Permafrost Carbon Feedback on Global Climate.)

But now, human fossil fuel burning is causing the Arctic to rapidly warm — at about 3 times faster than the rate of warming for the rest of the globe (0.6 C per decade in the Arctic). And with atmospheric CO2 concentrations presently above 400 parts per million (and CO2e concentrations above 490 parts per million), the world is now starting to thaw out of the icy period of the last 2-3 million years. As a result, the permafrost is melting.

But it’s not just Canada that’s feeling the thaw. In Siberia, warming is also eating away at the permafrost. And what is happening there is arguably on a much grander and more disturbing scale than what we presently see in Canada. In East Siberia, for example, a 100 meter deep, 1 kilometer long crater has formed in the sagging Permafrost. It is officially called the Batagaika crater. But the locals know it as the Gateway to the Underworld. The crater began as a small deformation during the 1960s when permafrost thaw in the region initiated. It has, over the decades, grown considerably larger — with the growth rate accelerating along with permafrost melt during recent years.

Further west, the Yamal region of Russia is seeing strange bulges dispersing across the land. The bulges, according to Russian scientists and to reports in the Siberian Times, are being caused by bubbles of methane gas beneath the surface. The scientists state that these formations are likely being triggered by warming — in which either methane hydrates trapped within the permafrost are thawing or where microbes have come in contact with thawed permafrost carbon to break it down and produce methane. And in recent years, this region of Arctic Siberia has seen some very warm temperatures — with readings hitting as high as 35 C (95 F) during the summer of 2016.

(The Yamal Crater was one of the first indications that methane pockets forming beneath the Siberian Tundra were starting to erupt due to human-forced warming. Image source: The Siberian Times.)

Touchy Subject Scientifically and Politically

Permafrost thaw producing high volumes of feedback carbon release can be a touchy subject in the sciences and politically. The reason is that rational responses to this threat moves decision points forward on human carbon emissions cuts and it adds to the concern that atmospheric carbon capture will be needed later this century and on through many centuries to follow in order to prevent a scenario in which carbon feedbacks cause a form of warming runaway.

It doesn’t help that the science on permafrost carbon feedback is also new and rife with uncertainty — generating a kind of gray area in which rumors and misinformation can multiply. And there also appears to be some indication that the fossil fuel industry is attempting to use the issue to push gas extraction and burning in the Arctic — falsely claiming that all of the gas is going to release anyway. Which is not true — a portion of the permafrost carbon and related methane would remain sequestered even as human extraction efforts, if they continued indefinitely, would ultimately result in the release of a much larger portion of this carbon to the atmosphere than mere feedbacks alone.

It is worth noting that presently accepted science indicates that the present rate of atmospheric carbon release due to fossil fuel burning is likely many times that of the potential annual carbon release coming from the permafrost even under the worst case warming scenarios. And because that realized rate of permafrost carbon release is directly tied to how much fossil fuel we ultimately burn, we should be very clear that the urgency to cut these emissions couldn’t be higher.

“Permafrost carbon emissions are likely to be felt over decades to centuries as northern regions warm, making climate change happen faster than we would expect based on projected emissions from human activities alone.” — Climate Change and the Permafrost Carbon Feedback

For a moment, let’s consider some rather difficult to deal with numbers —

790 billion tons — that’s the so-called ‘carbon budget’ the Intergovermental Panel on Climate Change (IPCC) estimates we need to stay within to prevent 2 degrees Celsius (3.6 degrees Fahrenheit) of warming in just this Century (note that current stated fossil fuel reserves hold enough carbon to exceed this budget many times over). It’s the level IPCC says we need to stay below to prevent ‘bad outcomes.’ A rate of warming that does not including later temperature increases in following centuries — which would be about double the 21st Century’s amount if global greenhouse gas levels managed to plateau and the global carbon stores remained on good behavior.

515 billion tons — that’s the amount of carbon humans have already emitted into the atmosphere. It leaves us with less than 275 billion tons remaining.

About 24 years — that’s how long it will take for humans to burn enough fossil fuels and emit enough carbon (at current and projected rates) to use up that ‘carbon budget.’ A break-neck pace of burning and dumping of carbon that is now probably about six times faster than at any time in the geological record. Faster than the atmospheric carbon accumulation during the last hothouse extinction — the PETM. Faster than during the worst hothouse mass extinction of all — the Permian.

Hitting Carbon Limits

Sound like we’re up against some hard limits? Well, we are. Because the above basically implies that human emissions would need to start falling dramatically now and get to near zero by 2050 to meet IPCC’s goal. A limit that, by itself, may have built in too much slack and may not have taken into account other responses from the Earth climate system.

0.6 degrees Celsius — that’s the pace at which the Arctic is warming each and every decade. According to the new study:

This is causing normally frozen ground to thaw — exposing substantial quantities of organic carbon to decomposition by soil microbes. This permafrost carbon is the remnant of plants and animals accumulated in perennially frozen soil over thousands of years, and the permafrost region contains twice as much carbon as there is currently in the atmosphere.

This amounts to about 1400 billion tons and around 1,000 billion tons in the shallow carbon store alone. A massive fireplug of carbon stored in thawing (and burning) land-based permafrost in the Northern Hemisphere at a shallow depth of zero to 3 meters. The new study expects 40 to 170 billion tons of this carbon store to release over the next 85 years. A further 120 to300 billion tons could hit the atmosphere by 2300 if the ongoing thaw in the north continues.

Averaging the report’s findings, we can add about 92 gigatons of baked-in feedback from the shallow permafrost zone alone and end up with 607 billion tons of carbon (human + expected permafrost). This leaves us with about 15 years before we are locked in to hit the ‘2 C limit’ of around 450 ppm CO2 by end Century (not considering a current 485 ppm CO2e level or end Century CO2e of 530 to 550 ppm when all other greenhouse gasses are added in).

In addition, the 120 to 300 billion additional tons from the shallow permafrost store expected to keep out-gassing through 2300 would ultimately result in a carbon pool that pushes atmospheric values up to 480-530 ppm CO2 (560 to 600 CO2e) and turns the ‘2 C limit’ into a 4-6 C (7.2 to 10.8 F) long term climate bake.

Carbon Debt With Compound Interest

Looking at the report’s numbers leaves us with the all-too-salient impression that we really don’t have a carbon budget at all. What we have is carbon bankruptcy. A carbon compounded debt shock enough to crack the whole of the Earth System carbon piggy bank and bleed out gigaton-sized carbon pennies for decades and centuries to come. And the new shallow permafrost carbon feedback estimate does not include the approximate 400 gigatons of carbon in the deep permafrost. Nor does it consider ocean carbon stores — which may provide their own carbon debt spiral. Nor does it include Antarctic carbon stores or a number of other possible stores that could be pushed out by heat stress.